1. Field of the Invention
The present invention relates to a thermal printer and projection coat print method, particularly relates to a technique for forming a protection coat on an image printed by a thermal printer.
2. Description of the Related Art
A thermal printer selectively drives a plurality of heat generating members arrayed in a main-scanning direction, and conveys an ink sheet and printing medium in a sub-scanning direction, thereby thermally transferring or sublimating ink in a dot line pattern on the printing paper to attain image forming.
Since the thermal printer can easily change a heat amount required to control a density of one pixel, it can relatively easily reproduce multi-tonality for one pixel, thus obtaining a smooth, high-quality image. A recent thermal printer can print an image having as high finishing quality as a silver halide photo since the performance of a thermal head and a material of printing paper are improved.
As for a technique for forming a protection coat layer on a printed image using this thermal printer, Japanese Patent No. 3861293 is known. Japanese Patent No. 3861293 describes a thermal printer which performs an image forming operation on a protection coat layer (laminate film) using a plurality of types of image forming data to form concaves/convexes on the surface of a printed material, thus realizing a matte finish (or matte finish).
However, the matte protection coat layer of a printed material by Japanese Patent No. 3861293 does not always have stable finish qualities, and as a result of dedicated examinations of the present inventors, it was revealed that the matte finish changed depending on print environments. Particularly, a thermal head temperature and environmental temperature (printer internal temperature) have great influences, and at especially a low temperature, a matte protection coat layer cannot often be formed.